Biomedical Engineering Reference
In-Depth Information
PET substrate
Patterned ITO
(a)
PM suspension
(b)
PET substrate
with continuous
ITO layer
+
(c)
Dried bR film
(d)
FIGURE 17.3
Fabrication process: (a) Patterned electrode surface is cleaned of all residues, (b) 100
L of PM suspension is
spread evenly over the patterned surface, (c) A 1.0-mm plastic spacer (not shown) is placed around the array to
separate the two electrodes, where the bottom ITO electrode is patterned and the top ITO electrode is continu-
ous, and they are connected to the positive and negative terminals of the power supply, respectively. An electric
field of 40 V/cm is then applied. (d) After drying, the top electrode is attached and sealed carefully along the
edge by using fast-curing epoxy resin.
bR-ITO-PET film spectrum (Figure 17.5c). A broad peak, from 550 to 580 nm, was observed
for the dried bR film. Successful deposition shows that the 570-nm absorption peak found
in the PM suspension is also preserved in the dried film. The peak is broader than the PM
suspension due to influences of dehydration on the Schiff base of bR retinal chromophore.
The dried film exhibits an optical density of approximately 0.5 due to high bR concentra-
tion in the film sample, which is greater than the bulk value of 0.3.
